Safety device for door operating mechanism



July 8, 1952 M. M. MATCHETT SAFETY DEVICE FOR DOOR OPERATING MECHANISM Filed Feb. 24, 1947 2 SHEETSSHEET 1 FIG.|.

INVENTOR.

MAHLON M. M ATGHETT ATTORNEYS y 8, 1952 M. M. MATCHETT SAFETY DEVICE FOR DOOR OPERATING MECHANISM 2 SHEETS-SHEET 2 Filed Feb. 24, 1947 INVENTOR. MAHLON M'.MATOHETT BY 2AM... M'M

ATTO RNEYS Patented July 8, 1952:

UNITED STATES PATENT OFFICE 14 Claims.

1 The present invention relates todoor operating mechanism and more particularly to a safety device associated therewith adapted to prevent injury and to improve the operation of power actuated garage doors and more particularly those ,of the overhead tilting type.

Iii-accordance with the present invention, actuating means for the door comprise a feed screw and a traveling nut associated between a' fixed portion of: the-building. and: a movabl'e portion of the door. Motor means are provided for rotating the feed screw and thus effecting travel of the nut soas to'move the door in opening or closing relation.-

It is desirable for avariety of reasons to provide means which permit disassociation between the driving connections or between the mounting of one of the driving connectionsand its associated part of the building structure. Thus, for example, in the case ofan overheadtilting door ona garage it isin many; cases; the only source ofingress or egress to the building. If, for example, there is a failure of the motor means or if a fuseor circuit breaker disconnects the power circuit to the motor, it hasin the' past been extremely difficult ifnot impossible toeffect entry into the garage without at the same time-damaging the power mechanism. Inother cases, movement of the garage door has brought it-into contact-with the operator or: other person. While-normally the power efiective to movethedooris such that n'o'injury' to the person thusengaged by the moving. door. results neverthelesait hasin the'past been possible for such person-to betrappedor firmly. held even though the motor ordriving actuatingmecl'ianism isstall'ed.

In accordance with" v the present invention; means are provided so that whenever the; forces acting on'the door exceed-apredetermined miniamount, separationordisas'sociationof ele'-'- ments ofthe power mechanism occurs-so thatthe do'o'r may be freely swung towardopenor closing osition; Thus, for. example, if'due tofailure of the motor itis desired to enter the garageitis necessaryonlytograsp the"usual operatinghandle provided on the door" and 'by. the. application of a relatively small force, the door may. be opened Without injury to" the power mechanism. Correspondingly; if the door in its closing ovement encounters" a person sta'ndingin the 'path thereof in su'ch a' manner as to efi'ectively trap or-imprison' him, .it is ,aneasy-- matter to release suchperson byapplying a relatively small-force'to the door in a door opening directi'om; The-release mechanism maybe provided of such effectiveness that the power ofthe motor-:iseifective torelease the driving mechanismifthe*doonencounters an immovable object or an object offering a-predetermined resistance to further movement of the door.

With the foregoing general remarks in mind, it is an object of the present invention toprovide safety mechanism for preventing accidents or injury to persons in connection with power actuated door operating mechanism.

. It is a further object of the present invention to provide door operating mechanism having associated therewith means for disconnecting the driving connectionsfor thedoor upon the application'of a relatively smallforce directly to the' ddorc.

More specifically, it is an object of the present invention to provide for disassociation of; elements of the driving connection whenever the forces acting on the door exceed a predetermined amount. 7 I I,

Merespecifically, it is an object of thepresent invention to provide means for eifecti ng automane opening and closihg inovement of a garage door which comprises a power drivenfeedscrew, a traveling nut, means for mounting the screw and nut between afixed portion of the building and arn'ovable portion of thedoor', andcpmbinajtion with releasable means for supportingorient the elements of the power driven mechanism whereby its disengagement may be effected when ever the force's'actingl on the doorexceed a predetermined amount. I M

It' is a' feature of'the present inventionto pro vide springpressed'fingers engageable with oppo sit'e sides of a traveling. nut wherebyapplication o'f force between the nut and spring pressed fingers Will efiot disengagement thereof.

Other obj eets and features of the invention will become apparent" as the description proceeds", especially when considered iii connection with the accompanying drawings, wherein? I v W Figure 1 is a fra mentary side elevation of the door operating mechanism;

Figure 2' is a fragmentary ri-tm elevation of the mechanism shown in Figure 1'; m

Figure 3 is an enlargedsectional view taken substantially ori the-line 3- 3 of Figural; and

Figure 4 is a dent elevation'of the traveling nut'emp'ieyed'; p I

For purposes of illustration, I the present invention is' illustrated as embodied in an overhead tilting garage door. It will be appreciated,-how- An overhead tilting garage door is mounted for tilting movement about the horizontal axis of a hinge support It. 'The upper edge of the door, when the door is in closed position, is indicated at E2 and it will be observed that the lower portion of the door swings outwardly, and since the door is pivoted intermediate its top and bottom edges, the upper edge l2 of the door swings inwardly.

Operating mechanism for the door it comprises a feed screw 28 rotatably supported in a housing or mounting 25, the screw 26 having thrust collars 22 and 23 mounted between arms 2d and 25 of the support 21. Thrust washers 26 and 21 are provided between the thrust collars 22 and 23 and the cooperating arms 26 and 25, respectively. Mounted on the screw housing or support 2| is an electric motor 36 which drives a small pulley 3i.

Rigidly connected to the screw 2! is a large pulley 32 which is adapted to be driven from the motor pulley 3! by a V-belt or the like 33.

Extending laterally from the door it and above the hinge ll when the door is in closed position is an actuating arm 36.

As best seen in Figure 2, the arm 413 is bifurcated at its free end to provide two arms 41 and G2. The arm or bracket 46 includes a reinforcing web portion 43 and an attaching flange 44 which is secured to the side edge of the door by suitable fastening elements indicated at 55.

The screw housing or support 2| is mounted for swinging movement in a vertical plane by a pivotal housing support 58 which is carried by a pivot bracket 55. The bracket is rigidly secured to a suitable rigid part of the garage structure adjacent the side of the door. In the present instance the bracket is illustrated as secured to a 2 x 6 spacer 52 extending between upright studdings 53. It will be appreciated, however, that any suitable rigid support may be provided for the bracket 5!. Preferably the housing support 50 is provided with a pair of arms 55 which span an outwardly projecting portion 56 of the bracket 5|,and is pivotally connected thereto by a pivot pin 57.

In order to transmit motion to the door It, a traveling nut 63} (Figure 3) is mounted between the arms 41 and d2 of the bracket 40. The nut 56 is internally threaded so as to have traveling threaded engagement with the feed screw and as will be apparent from Figure 1, rotation of the feed screw will result in motion of the nut along the feed screw accompanied by a relatively slight rotation of the feed screw about the axis of the pivot pin 51 and this will be effective to swing the door, from the open position indicated in full lines in Figure 1 to closed position, at which time the arm or bracket occupies the position indicated in dotted lines in this figure.

In order to provide for separation between the arm or bracket 49 and the nut 60, releasable means for engaging opposite sides of the nut 60 are provided. As best seen in Figure 3, eachof the arms t! and '32 is provided with a threaded openin in which is received an externally threaded cup 6!. A hollow plunger 62 is slidably received within the cup 6! and is provided with an outer rounded or spheroidal end 63. The plunger 62 is urged outwardly by a compression spring (it retained within the cup and a headed rod 65 is provided which extends through the spring 64, the head 66 of which engages the bottom of the spring receiving recess formed in the plunger 62. Movement of the rod 65 out of the cup BI is prevented by suitable means such as the cotter pin indicated at 61. The structure at opposite sides of the nut 60 is identical, and accordingly only one is described in detail.

The nut 60 may be of generally cylindrical shape and. at opposite sides thereof there are formed recesses for the reception of the rounded or spheroidal ends 63 of the plungers 62."

As best seen in Figure 4, the recesses 10 include a gradually sloped side wall portion indicated at H, the balance of the recess as indicated generally at 12 being spheroidal. The recesses 10 may conveniently be formed at opposite sides of the nut 60 by an end mill having a hemispherical end portion which is fed into the sides of the nut at an angle equal to the inclination of the sloped side wall portion 1 i.

Inasmuch as the ends 63 of the plungers 62 which engage in the recesses 10 arehemispherical or spheroidal, it will be apparent that the nut 60, being engaged by plungersBZ at opposite sides thereof, is held thereby against displacement but is permitted rotation about an axis established by the axes of the plungers 62. Furthermore, motion of the nut 69 downwardly as seen in Figure 3 is effective to apply a very strong force between members connected to the feed screw and nut supporting bracket 40, inasmuch as the outermost portion of the recesses 10 engage portions of the rounded ends 63 of the plungers throughout zones which approach parallelism to the direction of thrust. On the other hand, a relatively slight force applied in a direction to cause the nut 60 to move upwardly as seen in Figure 3 relative to the rounded ends 63 of the plungers will be effective to separate the nut from the plungers. In this case the sloped surfaces H of the recesses IE3 act as camming surfaces, with the result that the plungers 62 are forced outwardly into the cup member 6! against the resistance of the springs 64.

In the illustrated embodiment of the nut, it will be observed that the camming surfaces H are provided at one sideonly'of the recesses 10 so that the release mechanism is effective primarily'in response to forces acting in a single direction, such for example as forces applied manually to the door independent of the power mechanism in a direction tending to open the door. However, it is within the purview'of the present invention to provide corresponding camming surfaces at opposite sides of the recess so that the driving connections may'be disassociated in response to a predetermined force applied directly to the door independently of the power mechanism operating in either door opening or door closing direction. 'Further, it shouldv be noted that this permits an arrangement in which the power mechanism may be effective to separate the driving connections in the event that movement of the door is arrested intermediate its open or closed positionby. an object, such for example as an automobile parked too clo'seto the door, or an individual standing in the path of movement thereof. 'j f Therefore, if the tilting dooris the only means of access to the interior of they garagefand if for any reason such as power failure it is impossible to eifect power actuated opening of the door, it is possible to disengage the operating elements of the power driven door actuating mechanism by applying an opening force directly to the door. This will have the effectof forcing the rounded ends 63 of the plungers against the camming surfaces H of the nuts and thus. will cause the bracket 40 to become separated "from thenut 60. At. this time the cotter pins which prevent movementv ofithe rod '65 completely out of the recesses of the; cups 6! will also prevent complete separation of theplungers 62 therefrom. In order to reengage the plungers with the nut it is necessary only to bring the plungers into juxtaposition'to the nut and thereafter by appropriate movement of the pivoted feed screw to force the nut intoposition between the plungers where they will automatically engage into the recesses iii. The same operation may of course be effected in case a person is accidentally within the garage when the door is closed. Substantia'l ly the same ope-ration may be carried out if the door-accidentally closes upon a person in a manner to require reverse movement of the door to extrioatethe individual. As previously stated, the motoris of such power that normally injury to a person in the path of the door will not result, but even a slight force may of course be effective toprevent removal of the person caught between a fixed portion of a building and a movable portion of the door. In such case a relatively slight force applied directly to the door in a door opening direction will cause separation of the spring pressed plungers 62- and the nut 56. Y Y r Briefly reviewed, the safety mechanism, comprising the means for -separating the driving connections and more specifically for releasing the traveling nut from the normal support therefor, is effective under a variety of conditions. In the first place, it may be effective to release the nut if motion of the door is arrested in either opening or closing movement, in which case the power of the motor is effective to apply forces sufiicient to cam the rounded ends-63- of the plungers out of the recesses 70. In the second place, the strength of the springs 65 and the shape of the camming surface orsurfaces m-ay be such that if the doors motion is arrested, the motor will stall, the power of theimotor being such that the: forces applied by the door are. insufficient tocause injury to a person. In this case, with the motor stalled the individual may release the driving connections by applying a force to the door either a door opening or door closing :..dir.ection. Ln a. specific case the camming surfaces which would be effective to release the driving connections upon forces applied independently of the driving mechanism to the door in a door closing direction may be such as to require substantially greater forces to effect separation of the driving mechanism than is required in the opposite direction.

While there is illustrated and described in considerable detail the structure and application of asafety device to a particular door actuating mechanism, it will be appreciated that this full exposition has been given merely toenable those skilled in the art to practice the invention, thescope of which is indicated by the appended claims,

What I claim as my invention is: U1. In mechanism. for operating the door'of a building, apower driven screw: and a traveling nut adapted'to be interconnected betweenaimovable part. of, the. door and a. fixed partofthe building, means for. supporting said nut against rotation comprising a. bracket: having a bifurcatedportion forreceiving said-nut, and spring pressed nut engaging elements resiliently engaging opposite sides of said nut and normally retaining said nut againstrotation but effective upon application of a'predetermined force to said door to release said nut.

. 2'. In mechanism for operating the door of'a building, a power driven screw and a traveling nut'adapted to'be interconnected between amovable part of the door and a fixed part of the building, means for supporting said not against rotation comprising a bracket having a bifurcated portion for receiving said nut, and spring pressed nut engaging elements, said nut having recesses therein for receiving the ends of. said elements.

3. In mechanism for operating the door of a building, a power driven screw and a traveling nut adapted-to be interconnected between a movable part of the door and a fixed part of the building, means for supporting said nut against rotation comprising a bracket having a bifurcated portion for receiving said nut, and spring pressed nut engaging elements, said nut having recesses therein for receiving the ends of said elements, the ends of said elements and said recesses being shaped to provide a camming action eifective to move said elements out of said recesses upon application of a predetermined force to said door.

4. In mechanism for operating the door of a building, a power driven screw and'a traveling nut adapted to be interconnected between a movable -part of the door and a fixed part of the building, means for supporting said nut against rotation comprising a bracket having a bifurcated portion for receiving said nut, and spring pressed nut engaging elements, said nut having recesses therein for receiving the ends of said elements, the ends of said elements being rounded, the recesses in said nut being generally rounded but having gradually inclined camming side walls at one side effective to'force retraction of said spring pressed elements upon application of a predetermined force to said door in a predetermined direction.

5. In mechanism for operating the door of a building, a power driven screw and a traveling nut adapted to be,interconnectedbetween a movable part of the door and a fixed part of the building, means for supporting said nut against rotation comprising a. bracket having a bifurcated portion for receiving said nut, and spring pressed nut engaging elements, said nut having recesses therein for receiving. the ends of said elements, the ends of said elements being rounded, the recesses in said nut being generally rounded but having gradually inclinedcamming side walls at opposite sides effective to force retraction of. said spring pressed elements upon application of a predetermined force'to said door in either door opening ordoor closing direction.

6. In a building having a door mounted for swinging about a horizontal axis between open and closed position, door operating mechanism comprising a power driven screw adapted to be pivoted to a fixed portion of the building, a traveling nut on'said screw, a nut-supporting bracket adapted to be carried by a movable portion of the door, said bracket having releasable means for retaining saidnut against axial rotation while providing for pivotal movement about a transverse axis, said releasable means comprising means engaging opposite sides of'said out including a spring .pressed. plunger, and said nut having a plunger receiving recess in a side there- 7. In a building having a door mounted for swinging about a horizontal axis between open and closed position, door operating mechanism comprising a powerdriven screw adapted to be pivoted to a fixed portion of the building, a traveling nut on said screw, a nut-supporting bracket adapted to be carried 'by'a movable portion of the door, said bracket having a pairof spaced arms, spring pressed plungers carried by said arms, said nut having lateralrecesses for receiving said plungers.

8. In a building having a door mounted for swinging about a horizontal axis between open and closed position, door operating mechanism comprising a power driven screw adapted to be pivoted to a fixed portion of the building, a traveling nut on said screw, a nut-supporting bracket adapted to be carried by a movable portion of the door, said bracket having a pair of spaced arms, spring pressed plungers carried by said arms, said nut having lateral recesses for receiving said plungers, the ends of said plungers and said recesses being shaped to provide for pivotal movement of said nut about a transverse axis while retaining said nut against axial rotation.

9. In a building having adoor mounted for swinging about a horizontal axis between open and closed position, door operating mechanism comprising a power driven screw adapted to be pivoted to a fixed portion of the building, a traveling nut on said screw, a nut-supporting bracket adapted to be carried by a movable portion of the door, said bracket having a pair of spaced arms, spring pressed plungers carried by said arms, said nut having lateral recesses for receiving said plungers, the ends of said plungers and said recesses being shaped to provide for pivotal movement of said nut about a transverse axis while retaining said nut against axial rotation and further shaped to provide camming surfaces to effect separation between said nut and plungers upon application of a predetermined force to said door.

10. In a building having a door mounted for swinging about a horizontal axis between open and closed position, door operating mechanism comprising a power driven screw adapted to be pivoted to a fixed portion of the building, a traveling nuton said screw, a nut-supporting bracket adapted to be carried by a movable'portion of the door, said bracket having a pair of spaced arms, spring pressed plungers carried by said arms, said nut having lateral recesses for receiving said plungers, the ends of said plungers and said recesses being shaped to provide for pivotal movement of said nut about a transverse axis while retaining said nut against axial rotation and further shaped to provide camming surfaces to effect separation between said nut and plungers upon application of a predeterminedforce to said door in either door opening or door closing direction.

11. Safety release means for a nut associated with a power driven screw comprising a bracket having spaced arms for receiving a nut therebetween, a nut located between said arms and having recesses in its sides adjacent said arms, elements carried by said arms seated in said recesses comprising at least one spring pressed element, said elements and recesses comprising a pivot support for said nut.

12. Safety release means for a nut associated Witha power driven screw comprising a bracket having spaced. arms for receiving a nut therebetween, a nut located between said arms and having recesses in its sides adjacent said arms, elements carried by said arms seated in said recesses comprising at least one spring pressed element, saidv elements and recesses: comprising a pivot support for said nut, the sidesof said recesses being inclined to provide camming surfaces for effecting release of said nut by force applied laterally thereto.

13. Safety release means for a nut associated with a power driven screw. comprising a bracket having spaced arm members for receiving a nut member therebetween, a nut member located between said arm members, means between said nut member and arm members providing for rocking movement of said nut member about an axis extending between said arm members and effective to retain said nut member against rotation about its axis, said means comprising at least one pivot element carried by one of said members, a shallow recess on the adjacent member adapted to receive said element, yieldable means resiliently urging said element into said recess, said recess having gradually tapered edges operable as eamming surfaces to effect release of said nut member upon application of force in a direction transverse to the axis of said nut member.

14. Safety release means for a nut associated with a power driven screw, comprising a bracket having spaced arm members for receiving a nut member therebetween, a nut member located between said arm members, means between saidv nut member and arm members providing for rocking movement of said nut member about an axis extending between said arm members and effective to retain said nut member against rotation about its axis, said means comprising at least one pivot element carried by one of said members, a shallow recess on the adjacent member adapted to receive said element, yieldable means resiliently urging said element into said recess, said recess having a gradually tapered edge portion at one side thereof operable as a camming surface to effect release of said element upon application of force in a direction transverse to the axis of said nut member, said recess having a second more steeply inclined edge portion angularly spaced from said gradually tapered edge portion effective to retain said nut against torque imparted thereto by rotation of a feed screw associated therewith.

MAHLON M. MATCI-IE'I'I'.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 929,539 Bateman July 27. 1909 1,073,500 Leopold Sept. 16, 1913 1,139,905 Pitts May 18, 1915 1,274,722 Lacey Aug. 6, 1918 1,635,442 Sigurd July 12, 1927 1,788,491 Morse Jan. 13, 1931 1,870,992 Freuler Aug. 9, 1932 1,915,806 Talbot June 27, 1933 1,957,990 Austin May 8, 1934 2,198,427 Templeton Apr. 23, 1940 2,201,161 Deans May 21, 1940 2,221,039 Babcock Nov. 12, 1940 2,407,537 Chapman 1 Sept. 10, 1946 2,479,713 Beach Aug. 23, 1949 2,540,538 Matchett Feb. 6, 1951 FOREIGN PATENTS Number Country Date Great Britain Jan. 27, 1926 

